Effect of vibration excitation locations on structural damage detection using the CSLDV technique: Simulation and testing

In recent years, the CSLDV (Continuing Scanning LDV) technique has been developed to obtain the ODS (Operational Deflection Shape) of a structure within a very short period of time. The ability to predict and to measure the ODS of a vibrating structure suggests its use to increase the potential for structural damage detection, localization and severity assessment. Previous research based on simulation of some simple test cases showed the effect of excitation locations on structural damage detection. Four steel plates were acquired and a FEM model of that structure was produced. Modal analysis, theoretical and experimental, was performed on the plate to obtain eigenvalues and eigenvectors and to update the FEM model. This time, the damage was simulated either using two permanent magnets which could be attached and de-attached easily without compromise the integrity of the structure or reducing the thickness of some elements. Hence, 4 damaged plates were modelled in FE software upon the position of the damage. The simulation and testing of the ODSs and the MSE (Mean Square Error) of the 4 plate structures in the damaged and the undamaged cases were performed based on CSLDV measurement method and compared respectively. Results show effect of vibration excitation location in the damage detection.